Slip form apparatus for tapered piers



Feb. 4, 1969 c. A. ERIKSSON SLIP-FORM APPARATUS FOR. TAPERED PIERS Filed Dec. 2'7, 1966 Sheet CARL 'A. ERIKSSON BY ATTORNEYS FlG.. 1

Feb. 4, 1969 Filed Dec. 2'7, 1966 c. A, ERIKSSON SLIP-FORM APPARATUS FOR TAPERED PIERS Sheet 2 M4 INVENTOR.

CARL A. ERIKSSON BY ATTORNEYS Feb. 4, 1969 c. A. ERIKSSON SLIP-FORM APPARATUS FOR TAPERED PIERS Sheet Filed Dec. 27, 1966 FlG.. 8

INVENTOR. CARL A. ERIKSSON FIG .3

ATTORNEYS Feb. 4, 1969 c. A. ERIKSSON SLIP-FORM APPARATUS FOR TAPERED PIERS Filed Dec.

Sheet 4 INVENTOR.

CARL A. ERIKSSON fiwa, ATTORNEYS, v

United States Patent 7 Claims ABSTRACT OF THE DISCLOSURE A slip-form apparatus for making pairs of tapered concrete piers that lean towards each other comprising pairs of upwardly convergent guide rails, a horizontal carrier adjacent the guide rails and a slip form at each end of the carrier, each with side walls that are adjustable in length so that the cross-sectional dimensions of each form can be decreased as the carrier is raised.

Specification This invention relates to the construction of concrete structures and more particularly it relates to a slip-forming apparatus for building upwardly tapered concrete structures having a rectangular cross section.

Slip-forming as a techniques for building concrete structures has been utilized successfully heretofore on structures where the walls to be formed are vertical. Generally, the method entails the use of a double walled form that retains concrete as it is poured and then is moved progressively upwardly to receive more concrete at the top of the form as the earlier poured material below commences to set.

In the construction of raised roadways, bridge approaches and the like, it is necessary to provide concrete piers, and it is often more eflicient and desirable from an engineering standpoint to taper such piers upwardly towards a progressively smaller rectangular cross section. In addition, it is also often preferred to furnish such tapered piers in pairs that lean towards each other and are connected by a cap portion at their upper ends. Prior to the present invention no slip-forming apparatus was capable of producing such tapered pier structures, and it was necessary to erect conventional static concrete forms to form them as well as other tapered structures-a practice that was expensive in material, labor and time. An object of my invention, therefore, is to solve the aforesaid problem by providing a slip-form apparatus which eliminates the need for expensive conventional, static forms, and is operable to construct leaning and tapered concrete structures such as supporting piers and the like.

Another object of the present invention is to provide an apparatus for constructing a pair of solid concrete pier members which taper upwardly while leaning toward each other and are spaced so that they can ultimately be joined together at their upper ends by a structural cap,

Further objects of the present invention are to provide an apparatus for slip-forming a pair of upwardly tapered, leaning piers: (1) which enables the amount of taper of each pier member to be controlled within close tolerances; (2) which is easy to operate with a minimum labor force and is readily adaptable to automated control; and (3) which facilitates the erection of pier members rapidly with remarkable ease and economy.

Still another object of the present invention is to pro vide a concrete slip-forming apparatus which includes a carrier unit that supports a working platform as the slipforming takes place and then provides an additinoal support at the tops of the pier members after they have been formed for use in making a cap for connecting their top ends together.

A more specific object of my invention is to provide an apparatus for slip-forming tapered upright concrete piers with opposite for-m walls that are variable in length to control the cross-sectional dimensions of the form and hence the amount of taper of the piers within preselected limits.

A further object of my invention is to provide an apparatus for slip-forming tapered upright concrete walls including a form having at least one pair of walls whose :length i varied automatically as the form is raised.

Other objects, advantages and features of my invention will become apparent from the following detailed de scription of one embodiment thereof taken with the accompanying drawings and presented in accordance with 35 U.S.C. 112.

In the drawings:

FIG. 1 is a view in elevation showing a slip-forming apparatus embodying the principles of the present invention in use on a partially completed twin pier structure;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a view in side elevation of the apparatus of FIG. 1;

FIG. 4 is an enlarged fragmentary view in side elevation showing one end of the apparatus of FIG. 1;

FIG. 5 is an enlarged plan view of the apparatus shown in FIG. 4;

FIG. 6 is a greatly enlarged fragmentary plan view showing one corner of a slipform according to the invention;

FIG. 7 is a view similar to FIG. 6 after the form wall has been partially retracted;

FIG. 8 is a fragmentary view in side elevation showing one end of my slip-forming apparatus with a second position thereof shown in dotted lines.

Referring to the drawings, FIG. 1 shows a variable wall, slip-forming apparatus 20 embodying the principles of the present invention in position for constructing a concrete pier 22 comprised of a pair of spaced apart members 24. Each of the pier members taper individually and also converge together as they extend upwardly. Such piers may be used at spaced apart intervals to support bridges, as well as other structures such as elevated roadways or buildings. In FIG. 1, the pier members are shown partially completed with the apparatus 20 in operation, the dotted lines depicting the remaining uncompleted pier portions together with a connecting cap portion 26 that normally is added on top after the pair of upright pier members 24 are formed. In general, my novel slip-forming apparatus 20 comprises a support and guide frame structure 28 that is erected initially on the job site before the concrete pouring commences. This structure supports a movable horizontal carrier assembly 30, and attached to each end of the latter is a slip form 32. Each slip form is used in the well-known manner so far as concrete pouring, setting and slipping is concerned, but according to my invention, the plan form dimensions of each slip form are variable by a predetermined controlled amount to enable it to decrease in size as it is raised upwardly. As will be seen, this provides each pier member with a tapered cross section. When the twin leaning and tapered pier members have been slip formed to their upper limits the carrier unit 30 is retained temporarily to provide a support for a platform that may be used in constructing the cap portion 26 which interconnects the twin pier members 24 using conventional concrete forms and pouring techniques.

The apparaatus 20 will now be described in greater detail with reference to FIGS. 1 to 8. The support and guide frame 28 is preferably formed from structural steel members which may be precut and then assembled by bolts or welding on the job site. Essentially, it comprises a pair of A-frame sections 34 that are spaced apart at their lower ends but lean towards each other Slightly so that they are closer together at their upper ends. Each A-frame section is comprised of a pair of inclined I-beam members 36 that are spaced apart at their lower ends and converge as they extend upwardly. Between their upper and lower ends these latter members are connected by horizontal cross braces 38 which provide sufiicient strength and rigidity, and similar horizontal cross braces 40 are provided to connect the two A-frame sections 34 together.

The carrier unit 30 that supports the two slip forms 32 at its opposite ends and moves up the guide frame 28 preferably comprises a pair of horizontal I-beams 42 that are interconnected and extend adjacent to the opposite sides of the support frame. Both of the beams 42 have upper and lower flanges 44 and 46 on which are supported movable members connected to the slip forms.

Each slip form 32 is essentially an enclosure having a generally rectangular plan form with adjustable side and end walls so that its size can be varied as it is raised to form the tapered pier members 24. Thus, as shown in FIGS. 4 and 5, each form has one pair of side wall plates 48 that are fixed to either or both of the upper or lower flanges 44 and 46 of the horizontal support beams 42. A series of spaced apart, vertical stitfeners 50 are fixed to the outside of each side wall plate 48 and outwardly extending brackets 52 on these stiifeners are supported by the adjacent beam flange. The opposite end walls 54 of each slip form comprises a similar pair of rigid plates having the same height as and provided with spaced apart outside stiffeners 56 like the first side wall plates 48. These latter end wall plates 54 are each attached, as by brackets 58 on their stififeners 56 to a pair of upper and lower box beams 60 and 62 extending transversely between the support beams 42.

The upper box beams 60 each slidably fit within tubular support members 64 at each end and the lower box beams 62 fit within similar support members 64. Thus, for each slip form 32 there are eight such members that support four box beams, two of the latter being connected to each end wall plate 54.

Each support member 64 is fixed as by welding to a base plate 66 that is attached to but slidable along a flange 44 or 46 of a beam 42. As shown in FIG. 4a, each plate 66 is bolted through a spacer 68 to a somewhat smaller plate 70 on the inner opposite side of the beam flange, the two plates 66 and 70 being kept far enough apart so that this whole support member assembly is easily slidable on the beam flange 44.

At each of the four corners of each slip form 32 two of the connector beam support members 64 are also fixed to the upper and lower ends of an angular wall member 72 that forms a corner of the form and fits inside but adjacent to one each of the opposite wall plates 48 and 54. Each angular or corner wall member overlaps the adjacent flat side walls by a considerable amount and is slidable relative to these wall plates to vary the size of the slip forms as the horizontal carrier unit 30' is raised. To strengthen each corner wall member, I prefer to provide a reinforcing angle 74 along the outside corner edge, which may be fixed as by welding to both the adjacent support member 64 by a bracket 78 and to its base plate 66. A stringer 76, spaced from the corner reinforcing angle, may also be utilized to secure each support member 64 to its corner wall member 72.

Within each slip form 32 are four upright jack rods 80 that are spaced inwardly from its four corners and located substantially parallel to its longitudinally centerline. These rods 80 are preferably supported in pipes 82 that are anchored within the form in the conventional manner well-known in the art, and mounted on each rod extending above the upper edges of form walls in a suitable jack 84 that is threaded to the rod and is movable upwardly on it as the rod is turned. The jacks may be operated hydraulically or by any other suitable means. A pair of yoke beams 86 are fixed to opposite sides of two of the jacks and extend transversely across the form. Near their opposite ends these pairs of yoke beams are each connected by a bolt 88 to the upper end of an upright beam 90 that is parallel with the slip form centerline. These latter beams extend downwardly along the outside edges of the beam flanges 44 and 46, and each is connected to both an upper and a lower sliding base plate 66 attached to a corner connector. As shown in FIG. 4, this latter connection is accomplished by an angle bracket 92 that is welded to the base plate 66 and a bolt 94 that extends through the upright flange of the bracket and through the beam 90.

On the opposite sides of the slip forms 32, which are parallel with the support beam 42, a pair of upper and lower form adjusting rods 95 extend through the spaced apart upright beams 90. The ends of the aforesaid rods are threaded and tapered washers 96 are provided so that nuts 97 on the ends of the rods can be tightened to force the beams closer together. When this is done the sliding base plates 66 are moved on the flanges 44 and 46 of the support beam 42 causing the connector beam support members 64 to move toward each other along the beam 42 and the form side wall plates 48 to slide relative to the corner wall members 72, thereby reducing one dimension of the form.

In constructing a two-member pier with the apparatus 20 according to the present invention, the support and guide frame 28 is first erected with frame members 36 positioned a predetermined distance apart at their bases but inclined towards each other so that this distance decreases as they extend upwardly. Now, referring to FIGS. 5 and 6, fixed by means of a bracket 98 to each of the movable connector beam support members 64 near the inside end wall of each slip form is a guide roller 100 which is mounted so that its annular groove is aligned with and fits over the inner flange 102 of an A-frame beam member 36. Thus, as each slip form 32 is moved upwardly (see FIG. 8), the guide rollers 100 of each form are urged toward each other automatically thereby also forcing the connector beam support members and the attached corner plates 72 closer together. Attached to each connector beam support member having a guide roller 100 and at the opposite end therefrom is a pair of smaller stabilizing rollers 104 that are positioned on the opposite side 106 of the beam flange and help to maintain the slip form in its proper position on the beam 42.

When the support and guide frame 28 has been erected, the carrier assembly 30 is installed with the slip forms 32 at opposite ends thereof, the latter being located on top of footings which have been previously installed. With the forms and the jack rods 80 in place, a first pour can be made and in accordance with standard slip-forming technique, the concrete is allowed to set the amount necessary to facilitate raising of the form side and end walls. This raising is accomplished by simultaneous actuation of the jacks 84- on the rods 80 extending upward from each form. The forms are thus raised the desired amount which may be a matter of 1 to 4 inches and as this occurs, the guide rollers 100 are forced closer together by the inclined frame members 36 thereby causing the end Walls 54 of both forms to also move closer together. After raising the form the take-up nuts 97 on the rods 94 may also be tightened to move the upright beams 90 and thus the yoke beams 86 together which causes the corner wall members 72 of both slip forms 32 to come closer together along the beams 42. Thus, both slip forms are now re duced in two cross-sectional dimensions so a slight tapering of the pier members has been provided. The forms are now ready to receive more wet concrete before another raising and contracting cycle takes place. This cycle is repeated over and over until the desired pier height is reached.

When the twin pier members 24 that lean towards each other and also taper individually have been formed completely, the support beams 42 at the tops of the twin pier members 24 may provide an excellent support for a working platform for use in constructing the cap portion 26 of concrete extending across the tops of the press, as shown in FIG. 1. This may be accomplished by attaching the beams 42 to suitable brackets (not shown) that are retained by studs extending from the piers. The jacks, jack rods, yoke beams, side and end wall forms and the other connector beams can now be removed leaving only the support beams 42 attached to the pier members which can serve to support a platform. Thereafter conventional wood forms or other means can be provided to build the cap portion of the pier.

From the foregoing it should be apparent that my invention provides a unique apparatus for constructing pairs of concrete piers that lean towards each other and also taper upwardly. Not only can such piers be made relatively fast and with a remarkably small amount of labor, but the dimensions of the structure can be maintained with close tolerances as it is built and adjustments to correct irregularities can be easily made.

To those skilled in the art to which this invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. The disclosures and the description herein are purely illustrative and are not intended to be in any sense limiting.

I claim:

1. An apparatus for constructing a concrete pier member that tapers upwardly, said apparatus comprising in combination:

a support and guide frame including at least one pair of fixed guide rails that converge toward each other as they extend upwardly;

a movable form carrier extending transversely to said pair of guide rails;

a slip-form unit attached to said carrier having a pair of opposite side walls that are variable in length;

means for raising said movable form carrier upwardly along said guide frame;

means interconnecting the variable side walls of said slip-form unit to said guide rails and responsive to the raising of said carrier for decreasing the length of said variable walls and thus the cross-sectional shape of said form unit.

2. The apparatus as described in claim 1 including variable end walls on said slip-form unit and means for decreasing the length of said end walls by predetermined amounts.

3. An apparatus for constructing a pair of concrete pier members that lean toward each other and taper individually, said apparatus comprising in combination:

a support and guide frame including two pairs of guide rails, said pairs converging toward each other as they extend upwardly and each of said rails of each said pair also being inclined toward each other as they extend upwardly;

a movable form carrier extending transversely to said pairs of guide rails;

a pair of slip-form units attached near opposite ends of said carrier, each said unit having opposite Walls that are variable in length;

means for raising each said slip-form unit and thus said form carrier upwardly;

means interconnecting one pair of variable walls of each said slip-form unit to one said pair of guide rails and responsive to the raising of said carrier for decreasing the length of said adjustable side walls of both said slip-form units.

4. The apparatus as described in claim 3 wherein each said slip-form unit has opposite side walls connected by said latter means to said carrier and end walls that are also variable in length.

5. The apparatus as described in claim 4 wherein said Walls of each said slip-form are formed by side plates and end plates interconnected by overlapping corner wall members;

means fixed to said corner wall members and movable on said carrier unit to move said corner members relative to said side plates to vary the length of the form side walls;

a guide means fixed to each said latter means;

and beam means at opposite ends of each said form fixed to said end plates and having ends slidably retained by said guide means.

6. The apparatus as described in claim 5 including roller means on said guide means and engaged with one pair of said rails and responsive to movement upwardly along said rails to shorten the end walls of each said slip form.

7. An apparatus for constructing a pair of concrete pier members that lean toward each other and taper individually, said apparatus comprising in combination:

a support and guide means including a pair of connected A-frames which lean toward each other as they extend upwardly, each A-frame including a pair of rigid rails that converge upwardly;

a movable carrier comprising horizontal beams extending on opposite sides of said guide means;

spaced apart variable length transverse beams extending between said rigid beams;

mounting means movable axially on said rigid beams and slidably supporting the ends of said transverse beams;

a pair of adjustable slip-form units each located between pairs of said transverse beams and attached to said rigid beams of said carrier on opposite sides of said guide means, each said slip-form unit including a pair of opposite side wall plates fixed to said rigid beams, a pair of opposite end wall plates fixed to said transverse beams, and four corner wall members overlapping and slidably engaged with said side and end wall plates, each said corner wall member being fixed to a said mounting means;

jacking means extending above said slip-form units for raising them and said carrier by predetermined increments;

yoke beams attached to said jacking means;

upright members on opposite sides of each said slipform unit attached to a said mounting means and said yoke beams;

means for moving pairs of said upright members towards each other on opposite sides of each said s1ipform unit to decrease the side wall dimension thereof;

and roller means on said mounting means of each said slip-form unit adjacent to and engaging a pair of said guide rails for bringing said horizontal beams of said carrier closer together and thereby automatically shortening the end walls of the slip-form units as they and the carrier are raised.

References Cited UNITED STATES PATENTS 1,586,212 5/1926 Nemec 25-431 1,603,748 10/1926 Davis 249-49 3,363,873 1/1968 Barber et al 2491O X WILLIAM J. STEPHENSON, Primary Examiner.

DE WALDEN W. I ONES, Assistant Examiner.

US. Cl. X.R. 25-131 

